Troubleshooting
Si12-714
196
Service Diagnosis
5.14
Four Way Valve Abnormality
Remote
Controller
Display
EA
Outdoor Unit LED
Display
A
5
1
4
2
1
3
1
4
1
Method of
Malfunction
Detection
The liquid pipe thermistor, the outdoor temperature thermistor and the outdoor unit heat
exchanger thermistor are checked to see if they function within their normal ranges in the
operating mode.
Malfunction
Decision
Conditions
Either of the following conditions occurs 6 minutes after the compressor has started.
Cooling / dry operation
(Outdoor unit heat exchanger temperature – Liquid pipe temperature) < –5°C
Heating operation
(Liquid pipe temperature – Outdoor unit heat exchanger temperature) < 0°C
Supposed
Causes
Connector in poor contact
Thermistor defective
Outdoor unit PCB defective
Four way valve coil or harness defective
Four way valve defective
Foreign substance mixed in refrigerant